Apr 9, 2012

According to an international team of archaeologists and paleoecologists, early inhabitants of the Amazon forest farmed sustainably without the use of slash and burn methods. This conclusion was published on 9 April 2012 in the Proceedings of the National Academy of Sciences. This research is significant to finding sustainable conservation farming methods in the Amazon today, an area that is rapidly undergoing changes from industrial agriculture and cattle ranching.

Knowledge farming methods by early inhabitants of the Amazon is derived from analyzing records of pollen, charcoal and other plant remains over 2,000 years. The area studied was the Amazonian savannas in French Guiana. Early inhabitants used 'raised-field' farming, "which involved constructing small agricultural mounds with wooden tools. These raised fields provided better drainage, soil aeration and moisture retention: ideal for an environment that experiences both drought and flooding. The fields also benefited from increased fertility from the muck continually scraped from the flooded basin and deposited on the mounds. The raised-field farmers limited fires, and this helped them conserve soil nutrients and organic matter and preserve soil structure."

Funding for this study was provided by CNRS Programmes ('Amazonie' and 'Ingénierie Ecologique'), the Arts and Humanities Research Council and The Leverhulme Trust. The study was carried out by a team from:

University of Exeter (UK)

Natural History Museum of Utah (US)

Centre National de la Recherche Scientifique (France)

University of Edinburgh (UK)

Université Montpellier II

Centre d'Ecologie Fonctionnelle et Evolutive (France).

Comments from co-authors included:

* Dr José Iriarte of the University of Exeter, lead author on the paper, "this ancient, time-tested, fire-free land use could pave the way for the modern implementation of raised-field agriculture in rural areas of Amazonia."

* Professor Doyle McKey of the University of Montpellier added "Whereas savannas today are often associated with frequent fire and high carbon emissions, our results show that this was not always so."

* Dr Francis Mayle of the University of Edinburgh said: "We've got an unprecedented record of these Amazonian savannas that completely overturns previous assumptions about the way in which ancient cultures utilized these globally-important ecosystems."

* Dr Stephen Rostain of CNRS said "These raised-field systems can be as productive as the man-made black soils of the Amazon, but with the added benefit of low carbon emissions."